Arduino ePaper Clock Calendar Sketches

Collection of four sketches for creating an e-paper (e-ink) clock or calendar with an Arduino (Uno or Nano) and a Waveshares 2.9” e-paper screen.

Wiring

All the sketches assume the Arduino is wired as follows:

DS3231	Header Wire Colour	Arduino
SCL		A5
SDA		A4
VCC		5V
GND		GND
SQW		D2, for interrupt alarm, set with wakeUpPin()
Screen
BUSY	Purple	D7
DC	Green	D8
RST	White	D9
CS	Orange	D10
DIN	Blue	D11
CLK	Yellow	D13
VCC	Grey	3.3V
GND	Brown	GND
Arduino GND		D4 (Optional, connect to add 1 hour for daylight savings)

GxEPD2_with_two_fonts

Requires:

• GxEPD2

Test the GxEPD2 library for displaying graphics on the e-paper screen. Specifically showing how to use two different fonts on the same display.

See article Arduino E-paper Screen for more details.

sleep_wake_with_rtc

Requires:

• DS3232RTC
• LowPower

Use a DS3231 Real Time Clock module’s alarm function, and the low-power library to put the Arduino to sleep, and then wake it again.

See article Arduino & Real-Time Clock for more details.

epaper_clock

Requires:

• DS3232RTC
• LowPower
• GxEPD2
• U8g2 for Adafruit GFX

Displays the time, and date, on the e-paper screen, updating every minute. Puts the Arduino to sleep in between.

Use the SetSerial example sketch from the DS3232RTC Library (File -> Examples -> DS3232RTC -> SetSerial).

If you need to adjust between winter and summer time (plus 1 hour) set the time to winter time, then connect GND to pin D4, this will add 1 hour to the displayed time.

epaper_weekday_calendar - In Progress

Shows the day of the week in large letters across the top, and the date below in a smaller font. Updates daily at midnight, sleeps the Arduino in between.